In fact I could resolve the issue with a much simpler solution. I kept my Network, created a new site for the english then applied my theme and styling to it. Once that was done and only then I proceed as instructed below. You must do it in this order, otherwise it seem it create some kind of conflict with the theme.
Now as far as making a copy of the original site (pages, posts, menu, etc,... here are the instructions :
Go to the original site and Export with the WordPress Tools - Export menu - all the pages, posts and images from the original site then go to the new site and Import that (it's an .xml file) with the WordPress Tools - Import menu. To import you need to click on the WordPress link in the import window and it will instal what is call the “Importer” (it is a small plugin). Everything is done smoothly. If done in that order. Otherwise, when I imported the pages posts, menus, images, etc... before activating my theme and importing the CSS, it seem it was creating a conflict.
See the result at : http://www.groupeespaces.ca (original french version)
http://www.groupeespaces.ca/eng (Result from the copy of the whole french version that we will use to copy and paste the english content in the already created pages to avoid rebuilding everything from scratch ).
I must say that with the WordPress forum, I found all kind of complicated reply but only one person out of many thought to point me the Tools Export from WordPress (such a simple tool that I did not even think about it at first).
Thanks again for all your support.